Spring deck for furniture cushions



Jan. l5, 1963 J. G. PLATT 3,073,587

SPRING DECK FOR FURNITURE CUSHIONS lFiled Allg. 51, 1959 tats 3,073,587 Patented Jan. 15, 1963 3,073,587 SPRING DECK FR FURNliTURE CUSHIGNS .lohn G. liatt, Carthage, Mo., assignor to Flex--Lators, Inc., Carthage, Mo., a corporation ot' Missouri Filed Aug. 31, 1959, Ser. No. 837,203 4 Claims. (Cl. 267-103) This invention relates to new and useful improvements :in furniture spring assemblies, and has particular reference to spring assemblies of the type comprising a series of substantially planar spring units disposed in spaced apart vertical planes and each connected to a furniture frame only at its opposite ends.

The principal object of the present invention is the provision of a spring deck assembly composed of units of the class described in which the vertical depth of the assembly is quite small as compared to previous units of this type, in order to adapt them for use in the class of furniture called thin-line. This style of furniture, which is now enjoying substantial popularity, is characterized by seat cushions of a thin conguration, and also by comparatively high legs, as distinguished from the bulky overstuifed furniture in which the seats are extremely thick, often extending nearly or entirely to the floor and having extremely short legs or no legs at all. The class of spring units referred to have certain advantages in that they pack extremely compactly for convenience of shipping and handling, are very easily installed in the base frames of furniture by unskilled labor, and do not require specially formed furniture frames or complicated mounting structures. However, spring units of this class have heretofore been only poorly adapted for use in thin-line furniture. Due to the fact that each unit is disposed in a vertical plane, the convolutions or portions thereof, providing yieldability or softness must be disposed entirely below the portion forming the load-supporting platform of the spring deck, and the assembly thus inherently has a substantial vertical depth or thickness.

The objective of adapting this type of spring unit for use in thin-line furniture is accomplished by two principal innovations. Firstly, the end mountings of the unit a-re so altered that the unit is lowered so that it is disposed principally within the hollow seat frame of the furniture piece. Secondly, each spring unit is provided with an auxiliary spring member which is normally inoperative, but which when the assembly is flexed downwardly to a sucient degree, will engage and be flexed by engaging the rigid frame. In this manner the auxiliary members are caused to add their support to the assembly, resisting further deflection of said assembly. In this manner the total deflection of the assembly is decreased, thereby adapting it for use in thin-line furniture, without objectionably mpairing its initial softness or springiness.

Other objects are simplicity and economy of construction, ethciency and dependability of operation and adaptability for use in a wide variety of types and styles of furniture, as well as other types of seating structures.

With these objects in View, as well as other objects which will appear in the course of the specification, reference will be had to the drawing, wherein:

FIG. l is a top plan view of a furniture spring deck embodying the present invention, and

FIG. 2 is an enlarged sectional view taken on line II-II of FlG. 1, with parts broken away.

Like reference numerals apply to similar parts throughout the drawing, and the numeral 2 applies to a furniture seating frame, illustrated in its simplest form without the legs, back frame or other portions. As shown, it is formed of wood or other suitable material, and comprises a front rail 4,- back rail 6, and parallel side rails 8, all rigidly joined together. Secured in said frame is a spring assembly including a series of compound spring units 10 disposed in parallel vertical planes spaced apart regularly across the width of the frame. Each of said spring units comprising a plurality of elements, namely a main spring 12, a secondary spring 14, a stabilizing spring 16, and an auxiliary spring 13, all of said spring elements being formed of elongated at strips of spring steel or other suitable material.

n Main spring 12 includes a straight central portion 20 disposed above and approximately parallel to the plane of frame 2, and an inwardly converging il-formation at each end of said central portion, said V-formation including an inwardly and downwardly inclined leg 22 connected to central portion 20 by bend 24, and an outwardly and downwardly inclined leg 26 connected to leg 22 by bend 28. The forward leg 26 is extended to form a vertical leg 30 which is parallel to the inner face of front frame rail 4, and a horizontal terminal leg 32 which overlies the top surface of said rail. The rearward leg 26 is extended to form an upwardly and outwardly inclined leg 34 and a horizontal terminal leg 36 which overlies the top surface of back frame rail 6. l

Secondary spring element 14 is shaped similarly to ma-in element 12, having a central portion 38 which extends along central portion 20 of the main element in engagement therewith, but is of somewhat shorter length than portion 20. At the forward end of central section 38, secondary element 14 is extended to form, in sequence, a bend 49, a downwardly and inwardly inclined leg 42, a bend 44, an outwardly and downwardly inclined leg 46 which extends beneath and lies against leg 26 ofthe main element, a vertical leg 48 which lies against the inner surface of frame rail 4, a horizontal leg 50 which lies against the top surface of said rail, and a vertical terminal leg 52 which engages the outer surface of said rail. At the rearward end of central section 38, secondary element is extended to form, in sequence, a bend 54, a downwardly and inwardly inclined leg 56, a bend 58, an outwardly and downwardly inclined leg 60 which extends beneath and lies against the rearward leg 26 of the main element, an upwardly and outwardly inclined leg 62, and a horizontal terminal leg 64 which overlies the top surface of rail 6.

Stabilizing spring element 16 has an end portion 66 thereof extending longitudinally below and engaging central portion 38 of the secondary spring element. From the forward end of portion 66, the stabilizing element 16 is extended to form, in sequence, a bend 68, a rearwardly and downwardly inclined leg 70 which extends beneath and engages leg 6) of the secondary spring, a vertical leg 72 which engages the inner face or rail 6, a horizontal leg 74 which engages the top surface of said rail, and a vertical terminal leg 76 which engages the outer surface of said rail.

Auxiliary spring element 18 comprises a single straight strip which lies on the top of central portion 20 of the main spring element 12, but is of greater length than portion Ztl, extending both forwardly and rearwardly therefrom to such an extent that it extends over the top surface of front and back frame rails 4 and 6, although normally spaced above the frame.

At the forward end of the spring unit, legs 32 and 50 of -the main and secondary elements are gathered together in stacked relation on the top surface of front rail 4 and secured thereto by a nail 78 or other suitable means. At the rearward end of the spring unit, legs 36, 64 and 74 of the main, secondary and stabilizing elements are brought together in stacked relation on the top surface of rail 6 and secured thereto by nail 80. Adjacent the front rail, legs 26 and 46 of the main and secondary springs are secured together by a rivet 82, and adjacent back rail 6, legs 26, 60 and 70 of the main, secondary and stabilizing elements are connected by a rivet 84. A rivet 86 secures auxiliary element 13 to central portion 20` of the main spring, and to the forward end of central portion 38 of the secondary element.

A rivet 88 fastens auxiliary element 18 to the rearward end portion of central leg of the main element. Respectively at the opposite end portions of leg 66 of the stabilizing element, a pair of rivets 90 securely join leg 66, central portion 38 of the secondary element, central portion 20 of the main element, and the auxiliary element. Obviously clips or other securing means could be used in place of the various rivets described if desired.

The spring units 10 are interconnected by transverse spring strips 92 which extend transversely to the vertical planes of the units 10, laying on and intersecting the auxiliary elements 18 of each unit. A pair of these transverse strips are disposed respectively at the extreme forward and rearward edges of the spring deck, and are secured to elements 18 by a rivet 94 at each intersection therewith. Any desired number of strips 92 may be disposed intermediate the forward and rearward edges of the deck, and secured to elements 18 as by rivets 90.

In use, the spring units 10 and transverse strips are installed in frame 2 as already shown and described. The auxiliary spring elements 18, together with transverse strips 92, form the actual load-supporting platform of the spring deck. The assembly is then covered with suitable layers of padding and covering cloth, not shown, the edges of the cloth customarily being brought down over the edges of the spring deck and tacked or otherwise secured to frame 2 in a manner not pertinent to the present invention. The actual deck shown is intended primarily for use in the base portion of a couch or divan, in that loose spring or foam cushions are placed thereover, but it will be apparent that the invention is not limited to this usage. It will be seen that the top portion of each spring unit consists in its central portion of four strips, namely elements 66, 38, 20, and 18, and that these elements are of graduated length, so that the number of strips decreases in steps toward both the front and rear of the deck. 'This tends to produce a deck which is of uniform strength from its forward edge to its rearward edge, so that when a load is applied to the central portion thereof as by a person sitting thereon, the entire deck tends to be deflected downwardly in a more or less planar form, rather than dipping sharply at its central portion while its front and rearward edge portions remain elevated. This latter action, known as hammockingf is objectionable as causing discomfort, and has been a major defect in decks using spring units of the general class described, which due to their great overall span and lack of central support have commonly had a pronounced tendency to sag disproportionately when loaded in the middle. Stabilizing spring elements 16 have been found quite effective in preventing swaying of the deck from front to rear, and transverse strips tend to prevent swaying of the deck from side to side. Swaying in either of these directions creates a sensation in the user of movement or tilting, and is considered highly objectionable.

The features of construction and operation which specially adapt the deck shown for use in thin-line furniture are two in number. Firstly, the upward projection of legs and 48 at the forward end of the unit, and of legs 34, 62 and 72 at the rearward end of the unit, permit the major portion of the vertical extent of the unit to be dropped so that it is disposed within the hollow contines of frame 2 as shown. Clearly this permits a smaller vertical dimension than possible in previous structures wherein the entire spring units, or the major portions thereof, were disposed entirely above the frame.

Secondly, it will be apparent that in thin-line furniture, the total vertical yield of the deck must be less than in other furniture, to avoid bulging of the spring parts downwardly from the frame. Also, it is desirable that this limitation of the total yield be accomplished without interfering with the initial yieldability or softness of the deck, in order to avoid a sensation of stiffness or hardness when a person sits thereon. The present structure accomplishes these objects by means of auxiliary spring elements 18. When in the normal, unexed position shown in the drawing, the ends of elements 18 are disposed well above the rails 4 and 6, and the spring units are so designed that when this condition prevails, the deck will have the desired initial softness or springiness. Moreover, if the person sitting on the deck is sufficiently light of weight that the units will not be exed beyond the desired limit, the auxiliary springs will not engage the frame at all. However, if the person is heavy, the deck will be deliected to such an extent that the ends of auxiliary spring elements 18 will be engaged and deflected upwardly by the frame rails. The resilient stiffness of the end portions of elements 18 is thus added to the forces resisting deflection of the deck, and the total yield of the deck is thereby held within the desired limit. Elements 18 do not come into play until the persons weight is largely settled, and hence do not create a sensation of hardness or unyieldability as would occur if the elements 18 rested on the frame at all times. Moreover, since elements 18 are relaxed when they first engage the frame, they initially offer but little support to the deck and must be deflected to some degree before they do so. Hence there is no jolt or step in the yielding action of the deck as the elements 18 come into play.

Elements 18 also have the desirable attributes of supplying the means for changing the front to rear dimension of a spring deck by changing only one element of each unit, namely element 18. This is often desirable in that it permits adaptation of a single spring unit 10 to various types of seating, so long as the basic front to rear dimension of frame 2 remains the same, It should be noted that in many cases it may be possible and desirable to eliminate the rearward extension of elements 18, that is the portion of element 18 from rivet 88 rearwardly. This is possible since in many types of seating the back cushion of the chair extends substantially forwardly over the rearward portion of the spring deck of the seat. Hence the weight of a person sitting on the spring deck `will always be disposed well forwardly of back rail 6 of the frame, and the rearward portion of the spring deck is thus deflected downwardly to a much less extent than the forward edge. 'Ihe forward edge of the spring deck is virtually always subject to greater stresses, as by a person sitting on the edge of the cushion, or kneeling thereon. Hence the additional support supplied by element 18 is of primary importance only at the forward edge of the deck.

While I have shown and described a specific embodiment of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

l. A furniture spring deck comprising a rigid, hollow frame having a substantially planar upper surface and constituting a series of interenga ged walls; a plurality of spring units carried by said frame in parallel, horizontally spaced apart relation, each of said spring units being disposed in a substantially vertical plane and comprising an elongated length of resilient material having a generally straight central portion disposed above and generally parallel to the upper surface of said frame, and downwardly projecting end portions projecting substantially downwardly within said frame, said end portions each having a terminal portion extending upwardly adjacent a wall of said frame and affixed thereto, said spring unit being disposed within the confines of said frame so as to be deectable downwardly within said frame entirely below the upper surface thereof; and an elongated resilient auxiliary spring strip aixed to the central portion of each of said spring units and extending horizontally therefrom to overlie the upper surface of said frame, said auxiliary spring strips normally being disposed in spaced apart relation above said frame.

2. A furniture spring deck as recited in claim 1 wherein said auxiliary spring strips each extends the full length of the central portion of the spring unit to which it is axed, whereby to reinforce said central portion against iiexing in a vertical plane.

3. A furniture spring deck comprising a rigid, hollow frame having a substantially planar upper surface, a spring assembly mounted in said frame and having resiliently and downwardly yieldable portions disposed entirely within the counes of said frame so as to be movable downwardly therethrough, and auxiliary spring elements aflixed to the downwardly yieldable portions of said assembly and constituting elongated resilient members extending horizontally ontwardly from said assembly to overlie the top surface of said frame, said auxiliary spring elements being vertically yieldable and being spaced apart above said frame when said spring assembly is unflexed, whereby when said spring assembly is deeeted downwardly, said auxiliary spring elements will engage and be supported by said frame to increase the resistance of said assembly to further deection.

4. A furniture spring deck as recited in claim 3 wherein said auxiliary spring elements comprise flat spring strips which are straight and substantially free from tension except when they engage and are deflected by said frame.

References Cited in the le of this patent UNITED STATES PATENTS 1,915,390 Steele et al. June 27, 1933 2,250,486 Kronheim July 29, 1941 2,272,807 Kronheim Feb. 10, 1942 2,659,417 Handren Nov. 17, 1953 2,877,831 Burgert Mar. 17, 1959 FOREIGN PATENTS 55,898 Switzerland Sept. 18, 1911 466,900 Germany Oct. 13, 1928 551,666 Germany June 3, 19'32 636,443 Great Britain Apr. 26, 1950 

3. A FURNITURE SPRING DECK COMPRISING A RIGID, HOLLOW FRAME HAVING A SUBSTANTIALLY PLANAR UPPER SURFACE, A SPRING ASSEMBLY MOUNTED IN SAID FRAME AND HAVING RESILIENTLY AND DOWNWARDLY YIELDABLE PORTIONS DISPOSED ENTIRELY WITHIN THE CONFINES OF SAID FRAME SO AS TO BE MOVABLE DOWNWARDLY THERETHROUGH, AND AUXILIARY SPRING ELEMENTS AFFIXED TO THE DOWNWARDLY YIELDABLE PORTIONS OF SAID ASSEMBLY AND CONSTITUTING ELONGATED RESILIENT MEMBERS EXTENDING HORIZONTALLY OUTWARDLY FROM SAID ASSEMBLY TO OVERLIE THE TOP SURFACE OF SAID FRAME, SAID AUXILIARY SPRING ELEMENTS BEING VERTICALLY YIELDABLE AND BEING SPACED APART ABOVE SAID FRAME WHEN SAID SPRING ASSEMBLY IS UNFLEXED, WHEREBY WHEN SAID SPRING ASSEMBLY IS DEFLECTED DOWNWARDLY, SAID AUXILIARY SPRING ELEMENTS WILL ENGAGE AND BE SUPPORTED BY SAID FRAME TO INCREASE THE RESISTANCE OF SAID ASSEMBLY TO FURTHER DEFLECTION. 